"Australians work some of the longest hours in the developed world. So we have both a very large amount of casualisation but also some of the longest working hours in the world, so we've got two sides of the coin," she said.

"More and more people are working longer hours and more and more people are not getting the hours they want and that needs to be addressed.

"The statistics we had last year suggested that 2.2 million Australians don't know what time they'll finish work when they head out the door in the morning."

Casual work and low pay are key issues the ACTU is highlighting in its latest campaign for a rise in the award wage.

The unions want a $30-a-week increase for those on the lowest pay.

The wages of 1.5 million Australians are linked to the award.

But industry groups claim many small businesses owners are also just surviving.

Sydney florist Nicky Mann says she has no choice but to hire staff on casual or part-time contracts.

"Because I work in a seasonal industry, I need the flexibility of part-time labour for my business to survive," she said.